Generated by SassMeister.com.

input.scss

$wrap: 1920;

@function strip-unit($number) {
  @if type-of($number) == 'number' and not unitless($number) {
    @return $number / ($number * 0 + 1);
  }

  @return $number;
}

@mixin clamp($prop, $min, $max, $multi: (strip-unit($max) / $wrap) * 100vw) {
    #{$prop}: min(max(#{$min}, #{$multi}), #{$max});
    #{$prop}: clamp(#{$min}, #{$multi}, #{$max});
}

html {
    --family: -apple-system, Roboto, sans-serif;
    --h1: 3rem / 1.3 var(--family);
    --h2: 2.5rem / 1.3 var(--family);
    --h3: 2.25rem / 1.3 var(--family);
    @include clamp(--h1, 2rem, 3rem);
}

output.css

html {
  --family: -apple-system, Roboto, sans-serif;
  --h1: 3rem / 1.3 var(--family);
  --h2: 2.5rem / 1.3 var(--family);
  --h3: 2.25rem / 1.3 var(--family);
  --h1: min(max(2rem, 0.15625vw), 3rem);
  --h1: clamp(2rem, 0.15625vw, 3rem);
}

settings.json

{
  "sass": {
    "compiler": "dart-sass/1.32.12",
    "extensions": {},
    "syntax": "SCSS",
    "outputStyle": "expanded"
  },
  "autoprefixer": false
}